Apparatus for transferring substrates

ABSTRACT

The present invention relates to an apparatus for transferring a substrate. The apparatus includes a supporting member; an elevating and rotating member; a transferring unit; a first arm whose one end is supported by the elevating and rotating member to be rotatable; a second arm whose one end is supported by the transferring unit to be rotatable and whose the other end is supported by the other end of the first arm to be rotatable; and an arm driving part, installed on the first arm, which drives the other end of the second arm to pivot on the other end of the first arm to allow the first arm and the second arm to be folded or unfolded and thus removes the state of singularity by rotating the other end of the second arm based on the other end of the first arm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 14/044,192 filed on Oct. 2, 2013, said application claims theConvention priority date of Oct. 11, 2012, based on Korean PatentApplication No. 10-2012-0113222 and claims the Convention priority dateof Mar. 14, 2013, based on Korean Patent Application No. 10-2013-0027548and claiming the Convention priority date of Mar. 15, 2013, based onKorean Patent Application No. 10-2013-0028216, all incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus for transferring asubstrate.

BACKGROUND OF THE INVENTION

Substrates such as wafers for semiconductor devices and glass substratesfor either display units or thin film solar cells are manufacturedthrough several processes. At the time, substrates are loaded to, andprocessed at, a substrate processing device which provides optimalconditions required for each process.

Today, a cluster-type substrate processing device that may processsubstrates in batches has been developed and used to improveproductivity.

The cluster-type substrate processing device includes a load lockchamber where substrates are stored, a transfer chamber for transferringsubstrates, and multiple process chambers for performing respectiveprocesses. An apparatus for transferring substrates which is installedin the transfer chamber generally at a vacuum state transfers substratesbetween the load lock chamber and the transfer chamber, or between thetransfer chambers.

A substrate apparatus for transporting substrates published in KoreaLaid-Open Publication No. 10-2009-0008400 folds or unfolds anarticulated arm 31 by using a belt drive system 38 and transferssubstrates to be treated while a hand 32 makes a linearly reciprocatingmotion due to the articulated arm 31. However, because the apparatus fortransporting substrates folds or unfolds the articulated arm 31 by usingthe belt drive system 38, one side of the belt drive system 38 must benecessarily exposed to the outside. This may threaten to cause thesubstrates to be damaged by particles generated from the belt drivesystem 38.

A conveyance robot which solves such a problem is disclosed in JapanesePatent No. 4364001.

The conveyance robot is installed to allow an axis 31A formed on one endof a first link arm 31 to be rotatable on a swivel base 300 by a drivingunit such as a motor, and the other end of the first link arm 31 isinstalled to an intermediate link 33 to be rotatable. One end and theother end of a second link arm 34 are installed to a linear motion unit20 and to the intermediate link 33, respectively, to be rotatable.

As the first link arm 31 is normally or reversely rotated based on thecenter 01 of the axis 31A, the first link arm 31 and the second link arm34 are mutually folded or unfolded based on the intermediate link 33 andthis causes the linear motion unit 20 to give linear reciprocatingmotions. The linear motion unit 20 has multiple hands 21 on which worksW are loaded and supported.

Since the first link arm 31 of the conveyance robot is rotated based onthe axis 31A that is supported by a swivel base 300, when the other endof the first link arm 31 and that of the second link arm 34 are combinedtogether to be rotatable, and the virtual linear line connecting bothends of the first link arm 31 and that connecting both ends of thesecond link arm 34 are overlapped to become at the state of singularity,the second link arm 34 may also threaten to be rotatable due to therotation of the first link arm 31. As the first link arm 31 and thesecond link arm 34, then, cannot be folded or unfolded, the linearmotion unit 20 cannot give linear motions.

To prevent this, the other end of the first link arm 31 and that of thesecond link arm 34 of the conveyance robot are installed to theintermediate link 33 to be rotatable by being made to be mutuallyseparated and one end and the other end of a separate ancillary link arm32 are installed to the swivel base 300 and the intermediate link 33 tobe rotatable.

As shown above, the conventional conveyance robot may increase the costsdue to its complicate structure.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve all the problemsmentioned above.

It is another object of the present invention to provide an apparatusfor transferring substrates that saves costs.

In accordance with one aspect of the present invention, there isprovided an apparatus for transferring substrates, including: asupporting member; an elevating and rotating member installed to beelevated or descended and rotated on the upper side of the supportingmember; a transferring unit, which is installed on the elevating androtating member, for making linear motions to transfer substrates whenthe elevating and rotating member moves; a first arm whose one end issupported by the elevating and rotating member to be rotatable; a secondarm whose one end is supported by the transferring unit to be rotatableand whose the other end is supported by the other end of the first armto be rotatable; and an arm driving part, installed on the first arm,which drives the other end of the second arm to pivot on the other endof the first arm to allow the first arm and the second arm to be foldedor unfolded and thus removes the state of singularity by rotating theother end of the second arm based on the other end of the first arm toallow the second arm to be unfolded with the first arm even when thefirst arm and the second arm are arranged at an overlapped state whilethe first arm and the second arm move.

In accordance with another aspect of the present invention, there isprovided an apparatus for transferring substrates, including: asupporting member; an elevating and rotating member installed to beelevated or descended and rotated on the upper side of the supportingmember; a transferring unit, which is installed on the elevating androtating member, for making linear motions to transfer substrates whenthe elevating and rotating member moves; a first arm whose one end issupported by the elevating and rotating member to be rotatable; a secondarm whose one end is supported by the transferring unit to be rotatableand whose the other end is supported by the other end of the first armto be rotatable and which is bent; an arm driving part, which isinstalled on the first arm, drives the other end of the second arm topivot on the other end of the first arm to allow the first arm and thesecond arm to be folded or unfolded and thus removes the state ofsingularity by rotating the other end of the second arm based on theother end of the first arm to allow the second arm to be unfolded withthe first arm when a virtual linear line connecting both ends of thefirst arm and that connecting both ends of the second arm are arrangedat an overlapped state while the first arm and the second arm move.

In accordance with still another aspect of the present invention, thereis provided an apparatus for transferring substrates, including: asupporting member; an elevating and rotating member installed to beelevated or descended and rotated on the upper side of the supportingmember; a transferring unit, which is installed on the elevating androtating member, for making linear motions to transfer substrates whenthe elevating and rotating member moves; a first arm whose one end issupported by the elevating and rotating member to be rotatable; a secondarm which includes a pair of sub-arms and the respective sub-arms arebent whose one ends are supported by the transferring unit to berotatable and whose the other ends are supported by the other end of thefirst arm to be rotatable; and an arm driving part, which is installedon the first arm, drives the other end of the second arm to pivot on theother end of the first arm to allow the first arm and the second arm tobe folded or unfolded and thus removes the state of singularity byrotating the other end of the second arm based on the other end of thefirst arm to allow the second arm to be unfolded with the first arm whena virtual linear line connecting both ends of the first arm and thatconnecting both ends of the second arm are arranged at an overlappedstate while the first arm and the second arm move.

In accordance with still another aspect of the present invention, thereis provided an apparatus for transferring substrates, including: asupporting member; an elevating and rotating member installed to beelevated or descended and rotated on the upper side of the supportingmember; a transferring unit, which is installed on the elevating androtating member, for making linear motions to transfer substrates whenthe elevating and rotating member moves; a first arm whose one end issupported by the elevating and rotating member to be rotatable; a secondarm whose one end is supported by the transferring unit to be rotatableand whose the other end is supported by the other end of the first armto be rotatable; and an arm driving part, which is installed on thefirst arm, drives the other end of the second arm to pivot on the otherend of the first arm to allow the first arm and the second arm to befolded or unfolded and thus removes the state of singularity by rotatingthe other end of the second arm based on the other end of the first armto allow the second arm to be unfolded with the first arm when a virtuallinear line connecting both ends of the first arm and that connectingboth ends of the second arm are arranged at an overlapped state whilethe first arm and the second arm move, wherein the second arm is formedwith a material having a lower thermal expansion coefficient than thefirst arm.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention willbecome apparent from the following description of preferred embodimentsgiven in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of an apparatus for transferring substratesin accordance with a first example embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the bottom of FIG. 1.

FIG. 3A is a diagram showing the left of FIG. 2.

FIG. 3B is a magnifying view of part “A” in FIG. 3A.

FIG. 4A is an exploded perspective view of a first arm illustrated inFIG. 1.

FIG. 4B is an overview cross-sectional view of a driving axis, anelevating and rotating member, a spacing member and the first arms.

FIGS. 5A to 5D show motions of the apparatus for transferring substratesof FIG. 1 in accordance with the first example embodiment of the presentinvention.

FIG. 6 is a plan showing an arrangement of the first arm and the secondarm illustrated in FIG. 1 at the state of singularity.

FIG. 7 is a perspective view of an apparatus for transferring substratesin accordance with a second example embodiment of the present invention.

FIGS. 8A to 8D show motions of the apparatus for transferring substratesof FIG. 7 in accordance with the second example embodiment of thepresent invention.

FIG. 9 is a plan showing an arrangement of the first arm and the secondarm illustrated in FIG. 7 at the state of singularity.

FIG. 10 is a perspective view of the first arm and the second arm of theapparatus for transferring substrates in accordance with a third exampleembodiment of the present invention.

FIG. 11 is a plan showing an arrangement of the first arm and the secondarm illustrated in FIG. 10 at the state of singularity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed description of the present invention illustrates specificembodiments in which the present invention can be performed withreference to the attached drawings.

In the following detailed description, reference is made to theaccompanying drawings that show, by way of illustration, specificembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention. It is to be understood that the variousembodiments of the present invention, although different, are notnecessarily mutually exclusive. For example, a particular feature,structure, or characteristic described herein in connection with oneembodiment may be implemented within other embodiments without departingfrom the spirit and scope of the present invention. In addition, it isto be understood that the location or arrangement of individual elementswithin each disclosed embodiment may be modified without departing fromthe spirit and scope of the present invention. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined only by the appended claims,appropriately interpreted, along with the full range of equivalents towhich the claims are entitled. In the drawings, like numerals refer tothe same or similar functionality throughout the several views.

The apparatus for transferring substrates in accordance with exampleembodiments of the present invention will be explained by referring toattached diagrams in detail as follows:

First Example Embodiment

FIG. 1 is a perspective view of an apparatus for transferring substratesin accordance with a first example embodiment of the present invention;FIG. 2 is an exploded perspective view showing the bottom of FIG. 1;FIG. 3A is a diagram showing the left of FIG. 2; and FIG. 3B is amagnifying view of part “A” in FIG. 3A.

As illustrated, the apparatus for transferring substrates in accordancewith the first example embodiment of the present invention is installedon a floor of a transfer chamber of a cluster-type substrate processingdevice, and includes a supporting member 110 where a limited space isformed. The supporting member 110 may be formed in a variety of shapessuch as a cylindrical, hexahedral, or square shape.

On the upper side of the supporting member 110, an elevating androtating member 120 may be installed to be elevatable or descendable androtatable. The elevating and rotating member 120 is connected with theupper part of a driving axis 113 which is elevated or descended androtated by a driving unit (not illustrated) installed in the supportingmember 110, and it is elevated or descended and rotated by the drivingaxis 113.

In the elevating and rotating member 120, a transferring unit whichsupports and transfers a substrate 50 (Refer to FIG. 5A) is installed.The transferring unit transfers the substrate 50 by giving linearmotions while moving with the elevating and rotating member 120 at thesame time.

The transferring unit may include a fixed member 130, a sliding member140, and multiple hands 150.

The fixed member 130 is formed in a rectangular parallelepiped shapewith a certain length, and it is connected with the upper side of theelevating and rotating member 120 while its longitudinal direction isroughly in parallel with the transferring direction of the substrate 50.The sliding member 140 roughly lies at a right angle to the fixed member130 by being formed roughly in a shape as a square plate. Further, thesliding member 140 is installed to the fixed member 130 to be slid alongthe longitudinal direction of the fixed member 130. At the time, guiderails 130A (Refer to FIG. 3B) and guide grooves 140A (refer to FIG. 3B)guiding the motion of the sliding member 140 may be formed while thefixed member 130 is inserted into and combined with the sliding member140.

As one ends of the hands 150 are combined with the sliding member 140,the hands 150 move with the sliding member 140 and the substrate 50 isloaded on, and supported by, the other ends of the hands 150.

The fixed member 130 may include multiple first fixed members 131 andmultiple second fixed members 135 respectively installed on the upperside of the elevating and rotating member 120 and the sliding member 140may include a first sliding member 141 installed to the first fixedmembers 131 and a second sliding member 145 installed to the secondfixed members 135, respectively, to be slidable. On the upper side ofthe first sliding member 141, the second sliding member 145 may belocated.

The first fixed members 131 may be installed at the inside of the secondfixed members 135, and also on the upper side of the elevating androtating member 120 through the medium of a spacing member 133 (Refer toFIG. 2). In other words, the first fixed members 131 have a certaininterval from the upper side of the elevating and rotating member 120due to the spacing member 133.

A bracket 167 between the first fixed member 131 and the upper side ofthe elevating and rotating member 120 is placed to connect the firstfixed member 131 and a second arm 165 to be explained later.

One connecting plate 137 is combined with one ends of the first fixedmembers 131 and one ends of the second fixed members 135 in such a waythat one ends of the first fixed members 131 and one ends of the secondfixed members 135 are connected with each other.

Further, the other connecting plate 137 is combined with the other endsof the first fixed members 131 and the other ends of the second fixedmembers 135 in such a way that the other ends of the first fixed members131 and the other ends of the second fixed members 135 are connectedwith each other.

The hands 150 include multiple first hands 151 connected with the firstsliding member 141 and second hands 155 connected with the secondsliding member 145. Since the second sliding member 145 is located abovethe first sliding member 141, it is natural that the second hands 155are located on the upper sides of the first hands 151.

The first hands 151 and the second hands 155 are placed up and down tomake the first hands 151 load the substrate 50 and make the second hands155 unload it, or to make the first hands 151 unload it and make thesecond hands 155 load it. Accordingly, the apparatus for transferringsubstrates in accordance with the first example embodiment of thepresent invention may load or unload the substrate 50 at a time by usingthe first hands 151 and the second hands 155.

The sliding member 140 may give linear reciprocating motion while it isslid by the first arms 161 and the second arms 165.

In more detail, the first arm 161 may be formed in a case shape, and oneend thereof is supported by the one end of the elevating and rotatingmember 120 to be rotatable. At the other end of the first arm 161, arotation axis 161A is installed to be rotatable. Further, an arm drivingpart (not illustrated) including a motor 170 (Refer to FIG. 4A) rotatingthe rotation axis 161A, a gear and so forth may be installed in thefirst arm 161.

In addition, one end of the second arm 165 may be supported on one sideof the sliding member 140 to be rotatable, and the other end thereof maybe press-fitted with the rotation axis 161A. Therefore, when therotation axis 161A is rotated, the second arm 165 is also rotated.

In short, the arm driving part rotates the rotation axis 161A, and thesecond arm 165 pivots on the rotation axis 161A due to its rotation.This causes the first arms 161 and the second arms 165 to move in afolded or unfolded form. Due to folding or unfolding of the first arms161 and the second arms 165, the sliding member 140 is slid.

One pair of the first arm 161 and the second arm 165 and the other pairof the first arm 161 and the second arm 165 may be installed whilefacing each other across the transferring unit. Accordingly, one end ofeither of the first arms 161 is supported by one side of the elevatingand rotating member 120 to be rotatable. Further, one end of either ofthe second arms 165 connected with the above-mentioned one end of thefirst arm 161 is supported by one end of the first sliding member 141 tobe rotatable. Besides, one end of the other first arm 161 is supportedby the other end of the elevating and rotating member 120 to berotatable while one end of the other second arm 165 connected with theother first arm 161 is supported by one side of the second slidingmember 145 to be rotatable. Therefore, a first sliding member 141 isslid by either of the first arms 161 and either of the second arms 165and a second sliding member 145 is slid by the other first arm 161 andthe other second arm 165.

At this time, motions of either of the first arms 161 and either of thesecond arms 165 mutually connected and linked and those of the otherfirst arm 161 and the other second arm 165 mutually connected and linkedare independent. Accordingly, the first sliding member 141 and thesecond sliding member 145 give motions independently, and when thesubstrate 50 is unloaded by the first hands 151, the substrate 50 may beloaded by the second hands 155.

FIG. 4A is an exploded perspective view of the first arm illustrated inFIG. 1 and FIG. 4B is an overview cross-sectional view of a drivingaxis, an elevating and rotating member, a spacing member and the firstarm. The diagrams are explained in detail below.

As illustrated, the first arm 161 forms a certain space therein.Further, the first arm 161, with a shape of rectangular case, includes abody 162 whose at least either of the upper side or the undersurface isopened and at least one cover 163 combined to the upper side and/or theundersurface of the body 162. At the time, sealing members 164 may liebetween the body 162 and each cover 163 to seal the two.

As explained above, the rotation axis 161A connected with the other sideof the second arm 165 is installed on the other end of the body 162which corresponds to the other end of the first arm 161 and the armdriving part is installed in the body 162 to rotate the rotation axis161A.

However, external power must be supplied to the arm driving part to runthe arm driving part. To do this, the driving axis 113, the elevatingand rotating member 120, and the spacing member 133 are interconnectedso that paths 113A, 120A and 133A where cables (not illustrated) arepassed can be formed through the driving axis 113, the elevating androtating member 120, and the spacing member 133 respectively. Even onthe bottom surface of the body 162, a path 161B through which the cablesare passed is formed.

The motions of the apparatus for transferring substrates in accordancewith the first example embodiment of the present invention are explainedby referring to FIGS. 5A to 5D. FIGS. 5A to 5D, which are plans of FIG.1, shows the motions of the apparatus for transferring substrates inaccordance with the first example embodiment of the present invention.

As the sliding motion of the first sliding member 141 is same as that ofthe second sliding member 145, only sliding of the first sliding member141 is explained.

In FIG. 5A, it is supposed that the first arm 161 is located on theright side of the second arm 165 (i.e., on the right side from theviewpoint of a person who watches FIG. 5A; and explanation in the otherparts of this specification is similar to this), and it is supposed thatthe state of the first arm 161 and the second arm 165 which are unfoldedbased on the rotation axis 161A is an initial state. At the stateillustrated in FIG. 5A, the first hands 151 located under the secondhands 155 are hidden by the second hands 155.

When the rotation axis 161A rotates clockwise from the state illustratedin FIG. 5A by the arm driving part installed in the first arm 161, thesecond arm 165 rotates in a clockwise direction based on the rotationaxis 161A. Then, as one end of the first arm 161 is supported by theelevating and rotating member 120, the first arm 161 and the second arm165 move to a direction of being folded while being closer with eachother based on the rotation axis 161A as illustrated in FIG. 5B.

When the second arm 165 further rotates clockwise from the stateillustrated in FIG. 5B by the arm driving part, a virtual linear lineconnecting both ends of the first arm 161 and that connecting both endsof the second arm 165 are overlapped and become parallel, and become atthe state of singularity, as illustrated in FIG. 5C.

When the second arm 165 further rotates clockwise from the stateillustrated in FIG. 5C by the arm driving part, the second arm 165becomes located on the right of the first arm 161 and then the first arm161 and the second arm 165 become at the unfolded state as illustratedin FIG. 5D. In other words, as the second arm 165 pivots on the partsupported by the first arm 161, even though the first arm 161 and thesecond arm 165 are arranged at the state of singularity, the second arm165 can rotate easily. Therefore, the second arm 165 is easily out ofthe state of singularity, and it becomes unfolded with the first arm161.

Then, the first sliding member 141 gives a linear motion from left toright by the second arm 165 and thus the first hands 151 move from leftto right by the first sliding member 141. Accordingly, the substrate 50may be transferred.

Thereafter, when the second arm 165 rotates counterclockwise, i.e., in areverse direction, from the state illustrated in FIG. 5D by the armdriving part, the first arm 161 and the second arm 165 become at thestate illustrated in FIG. 5A, which is the initial state.

As the first sliding member 141 and the second sliding member 145 areindependently slid, when the substrate 50 is unloaded by the first hands151, other substrate can be loaded by the second hands 155.

The second arm 165 of the substrate processing device in accordance withthe first example embodiment of the present invention pivots on theother end of the second arm 165, i.e., an end where the second arm 165is exposed outside the sliding member 140, in a clockwise or acounterclockwise direction by the arm driving part. Accordingly, thefirst arm 161 and the second arm 165 may be unfolded easily even at thestate of singularity.

FIG. 6 is a plan showing an arrangement of the first arm and the secondarm illustrated in FIG. 1 at the state of singularity. FIG. 6 isexplained as shown below.

As illustrated, when the first arm 161 and the second arm 165 arearranged at the state of singularity, a vertical distance L1 from thefirst arm 161 to the side of the first fixed member 131 of the fixedmember 130 based on the rotation axis 161A may be equal to a verticaldistance L2 from the second arm 165 to the side of the first fixedmember 131 of the fixed member 130 based on the rotation axis 161A toallow the first arm 161 and the second arm 165 to be unfolded.

Reversely, based on the rotation axis 161A, the vertical distance L1from the first arm 161 to the side of the first fixed member 131 of thefixed member 130 may be equal to the vertical distance L2 from thesecond arm 165 to the side of the first fixed member 131 of the fixedmember 130 to allow the first arm 161 and the second arm 165 to beeasily folded.

However, in general, the lengths of the first arm 161 and the second arm165 may become longer by being thermally deformed because the apparatusfor transferring substrates is used in a high temperature environment.The lengths become further longer because the second arm 165 whose oneend is supported by the sliding member 140 is much more influenced overheat generated by the substrate processing device in the hightemperature environment and a hot substrate. More specifically, thesecond arm 165 is further more influenced over heat because the secondarm 165 is located at a relatively much closer place to the substrateprocessing device at the moment that the substrate is loaded to orunloaded from the substrate processing device.

When the first arm 161 and the second arm 165 are arranged at the stateof singularity, the second arm 165 becomes fit tightly to the rotationaxis 161A due to the extension of the second arm 165. Then, according tothe prior art, great strength is required to get out of the state ofsingularity by rotating the second arm 165.

To prevent this, as for the apparatus for transferring substrates inaccordance with the first example embodiment of the present invention,it is desirable to form the second arm 165 which is much influenced byheat with a more heat-resistant material than the first arm 161 which isrelatively less influenced due to the substrate processing device in thehigh-temperature environment.

In brief, it is desirable to form the second arm 165 with a materialhaving a lower thermal expansion coefficient than the first arm 161, andmore desirably, that the first arm 161 is made of aluminum and thesecond arm 165 is made of steel.

Then, as the second arm 165 is less deformed by heat, it is possible torotate the second arm 165 with small force to be out of the state ofsingularity.

In the first arm 161 in a case shape that includes the body 162 and thecover 163, a cooling system (not illustrated) such as a cooling tube maybe installed.

Second Example Embodiment

FIG. 7 is a perspective view of an apparatus for transferring substratesin accordance with a second example embodiment of the present invention.Only the differences from the first example embodiment are explainedbelow.

As illustrated, a second arm 265 may be formed in a bent shape includinga first body part 265A and a second body party 265B and one and theother end of the second arm 265 correspond, respectively, to an end ofthe first body part 265A and that of the second body part 265B.

Therefore, the end of the first body part 265A is supported by a slidingmember 240 of the transferring unit to be rotatable, and that of thesecond body part 265B is press-fitted with a rotation axis 261A androtated by the arm driving part. As the second body part 265B pivots onthe rotation axis 261A, which corresponds to the other end of the firstarm 261, the first arm 261 and the second arm 265 move in a form ofbeing folded or unfolded.

The first body part 265A and the second body part 265B may be formed inone body, but they would not be limited thereto.

FIGS. 8A to 8D which are plans of FIG. 7 showing the motions of theapparatus for transferring substrates in accordance with the secondexample embodiment of the present invention are explained below.

As the sliding motion of the first sliding member 241 is same as that ofthe second sliding member 245, only sliding of the first sliding member241 is explained.

In FIG. 8A, it is supposed that the first arm 261 is located on theright side of the second arm 265 (i.e., on the right side from theviewpoint of a person who watches FIG. 8A; and explanation in the otherparts of this specification is similar to this), and it is supposed thatthe state of the first arm 261 and the second arm 265 which are unfoldedbased on the rotation axis 261A is an initial state. At the stateillustrated in FIG. 8A, the first hands 251 located under the secondhands 255 are hidden by the second hands 255.

When the rotation axis 261A rotates clockwise from the state illustratedin FIG. 8A by the arm driving part installed in the first arm 261, thesecond arm 265 rotates in a clockwise direction based on the rotationaxis 261A. Then, as one end of the first arm 261 is supported by theelevating and rotating member 220, the first arm 261 and the second arm265 move to a direction of being folded while being closer with eachother based on the rotation axis 261A, as illustrated in FIG. 5B.

When the second arm 265 further rotates clockwise from the stateillustrated in FIG. 8B by the arm driving part, a virtual linear lineconnecting both ends of the first arm 261 and that connecting both endsof the second arm 265 are overlapped and become parallel, and become atthe state of singularity as illustrated in FIG. 8C.

When the second arm 265 further rotates clockwise from the stateillustrated in FIG. 8C by the arm driving part, the second arm 265 islocated on the right side of the first arm 261, the first arm 261 andthe second arm 265 become at the unfolded state as illustrated in FIG.8D. In other words, as the second arm 265 pivots on the part supportedby the first arm 261, even though the first arm 261 and the second arm265 are arranged at the state of singularity, the second arm 265 rotateseasily. Therefore, while the second arm 265 is easily out of the stateof singularity, it becomes unfolded with the first arm 261.

Then, the first sliding member 241 gives a linear motion from left toright by the second arm 265 and thus the first hands 251 move from leftto right by the first sliding member 241. Accordingly, the substrate 50may be transferred.

Thereafter, when the second arm 265 rotates counterclockwise, i.e., in areverse direction, from the state as illustrated in FIG. 8D by the armdriving part, the first arm 261 and the second arm 265 become at thestate as illustrated in FIG. 8A, which is the initial state.

As the first sliding member 241 and the second sliding member 245 areindependently slid, when the substrate 50 is unloaded by the first hands251, other substrate 50 can be loaded by the second hands 255.

The second arm 265 of the substrate processing device in accordance withthe second example embodiment of the present invention pivots on theother end of the second arm 265, i.e., an end where the second arm 265is exposed outside the sliding member 240, in a clockwise or acounterclockwise direction by the arm driving part. Accordingly, thefirst arm 261 and the second arm 265 may be unfolded easily even at thestate of singularity.

FIG. 9 is a plan showing an arrangement of the first arm and the secondarm illustrated in FIG. 7 at the state of singularity. FIG. 9 isexplained below.

As illustrated, when the first arm 261 and the second arm 265 arearranged at the state of singularity, a vertical distance L1 from thefirst arm 261 to the side of the first fixed member 231 of the fixedmember 230 may be equal to a vertical distance L2 from the second arm265 to the side of the first fixed member 231 of the fixed member 230based on the rotation axis 261A to allow the first arm 261 and thesecond arm 265 to be unfolded.

Reversely, based on the rotation axis 261A, the vertical distance L1from the first arm 261 to the side of the first fixed member 231 of thefixed member 230 may be equal to the vertical distance L2 from thesecond arm 265 to the side of the first fixed member 231 of the fixedmember 230 to allow the first arm 261 and the second arm 265 to beeasily folded.

However, in general, the lengths of the first arm 261 and the second arm265 may become longer by being thermally deformed because the apparatusfor transferring substrates is used in the high temperature environment.The length becomes further longer because the second arm 265 whose oneend is supported by the sliding member 240 is much more influenced overheat generated by the substrate processing device in the hightemperature environment and a hot substrate.

When the first arm 261 and the second arm 265 are arranged at the stateof singularity, the second arm 265 becomes fit tightly to the rotationaxis 261A due to the extension of the second arm 265. Then, according tothe prior art, great strength is required to get out of the state ofsingularity by rotating the second arm 265.

But the second arm 265 of the apparatus for transferring substrates inaccordance with the second example embodiment of the present is formedin a bent shape, including the first body part 265A and the second bodypart 265B. To shrink the length of the second arm 265 which is extended,the boundary zone of the first body part 265A and the second body part265B may be bent to the direction of being folded or unfolded.

However, because the second arm 165 in accordance with the first exampleembodiment of the present invention illustrated in FIG. 6 is a lineartype, when the first arm 161 and the second arm 165 are arranged at thestate of singularity, the second arm 165 must be shrunk by acting forcein a direction parallel in its longitudinal direction to get out of thestate of singularity.

It is natural that the force of shrinking the second arm 265 which isslightly bent to a direction of unfolding or folding the boundary zoneof the first body part 265A and the second body part 265B thereof, asillustrated in FIG. 9 is much less than that of shrinking the second arm165 in a direction in parallel to the vertical direction of the secondarm 165 as illustrated in FIG. 6. It is because hardness of the secondarm 265 is lower than that of the second arm 165 assuming that thesecond arm 265 and the second arm 165 were manufactured in a samecondition in comparison.

The length of the first body part 265A of the second arm 265 may be sameas, or longer or shorter than, that of the second body part 265B.Further, the first body part 265A and the second body part 265Bthemselves may be linear and may be formed in an arch shape as well.

As explained above, the second arm 265, formed in a bent shape, may beeasily rotated with relatively less force by extending or shrinking itat the state of singularity. Because the second arm 265 which isarranged at the state of singularity is extended or shrunk by lessforce, and the hardness of the second arm 265 is lower than that of thesecond arm 165, when the second arm 265 returns to the initial state byits elasticity from the extended or shrunk state, repulsive power isreduced. Therefore, it brings the effect of reducing shock andvibration.

It is natural that the apparatus for transferring substrates inaccordance with the second example embodiment of the present inventionmay also form the second arm 265 with a more heat-resistant materialthan the first arm 261. In other words, the second arm 265 may be formedwith a material having a lower thermal expansion coefficient than thefirst arm 261, and more desirably, the first arm 261 is made of aluminumand the second arm 265 is made of steel. It is natural that a coolingsystem (not illustrated) such as a cooling tube in the first arm 261 maybe installed.

When a transferring distance of the substrate 50 is long, the lengths ofthe first arm 261 and the second arm 265 must be extended longer.Accordingly, hardness of the first arm 261 and the second arm 265 mustbe higher. Further, when the weight of the substrate 50 is heavy, thehardness of the first arm 261 and the second arm 265 must be higher. Thefirst arm 261 may secure enough hardness because it is formed in a caseshape, but the second arm 265 is formed in a bar shape. Accordingly, toimprove hardness of the second arm 265, the thickness thereof must beincreased.

An apparatus for transferring substrates in accordance with the thirdexample embodiment of the present invention whose hardness is improvedwithout being thicker is explained below.

Third Example Embodiment

FIG. 10 is a perspective view of the first arm and the second arm of theapparatus for transferring substrates in accordance with a third exampleembodiment of the present invention and FIG. 11 is a plan showing anarrangement of the first arm and the second arm illustrated in FIG. 10at the state of singularity. Only the differences from the secondexample embodiment are explained below.

As illustrated, the second arm includes a pair of sub-arms 365 and 366and a pair of sub-arms 365 and 366 are made while the sub-arms 365 and366 are symmetrical to each other.

At the time, ends of first body parts 365A and 366A of the sub-arms 365and 366 are supported by a first sliding member 341 of the slidingmember 340 of the transferring unit to be rotatable, and ends of secondbody parts 365B and 366B are supported respectively to the other end ofthe first arm 361 to be rotatable and at the same time they are rotatedby the arm driving part. It is desirable that the first body part 365Aof the sub-arm 365 and the first body part 366A of the sub-arm 366 whichare supported by the sliding member 340 to be rotatable are concentricto the center of rotation supported by the sliding member 340, and thesecond body part 365B of the sub-arm 365 and the second body part 366Bof the sub-arm 366 supported respectively by the first arm 361 to berotatable are concentric to the center of rotation supported by thefirst arm 361.

Because the sub-arms 365 and 366 are paired, it is natural that it ispossible to improve hardness without increasing thickness of thesub-arms 365, 366.

If the sub-arms 365 and 366 are bent to shrink or extend the sub-arms365 and 366, forces in a vertical direction and in a horizontaldirection are at work, respectively, to the sub-arm 365 and the sub-arm366. Because the force in the horizontal direction at work to thesub-arm 365 offsets that to the sub-arm 366, it is possible to shrink orextend the sub-arms 365 and 366 with relatively less force.

In short, the force required to shrink or extend the second arm, i.e.,the sub-arms 365 and 366 in a pair, in accordance with the third exampleembodiment of the present invention is not increased in proportion tothe force necessary to shrink or extend the second arm 265 in accordancewith the second example embodiment of the present invention.

The sub-arms 365 and 366 arranged symmetrically in a pair wereexemplarily illustrated, but it is natural that the present invention isnot confined thereto. In other words, the pair of the sub-arms 365 and366 may be asymmetrical. In addition, the sub-arms are not necessary tobe composed as two arms, but they might be three or more arms.

Assuming that the second arm 265 in accordance with the second exampleembodiment of the present invention were formed as a pair just like thesub-arms 365 and 366 in accordance with the third example embodiment ofthe present invention, the second arm 265 might be thinner.

In the apparatus for transferring substrates in accordance with thepresent invention, the end of the second arm connected with the end ofthe first arm exposed outside the sliding member rotates clockwise orcounterclockwise by the arm driving part. Accordingly, even though thevirtual linear line connecting both ends of the first arm and thatconnecting both ends of the second arm are overlapped and paralleled atthe state of singularity, the first arm and the second arm are easilyunfolded. Accordingly, only with the first arm and the second arm, thesliding member where hands are installed may be easily slid. Therefore,it may save costs due to the simple structure.

In addition, since the second arm much influenced by heat is formed withthe more heat-resistant material, the second arm is relatively lessdeformed. Accordingly, it is possible to rotate the second arm with lessforce to get out of the state of singularity.

Furthermore, the other end of the second arm connected with the otherend of the first arm may be bent. In this case, even though the lengthsof the first arm and the second arm are deformed due to heat, etc., itmay bring an effect of making the second arm get out of the state ofsingularity by rotating the second arm with less force.

The detailed outlines of the drawings of the example embodiments of thepresent invention as described above are omitted, but exemplarilyillustrated to easily identify parts belonging to technological thoughtof the present invention. In addition, the example embodimentsabovementioned must not be references to confine the technologicalthought of the present invention, but only referential matters tounderstand technological matters included in the patent claims of thepresent invention.

What is claimed is:
 1. An apparatus for transferring substrates,comprising: a supporting member; an elevating and rotating memberinstalled to be elevated or descended and rotated on the upper side ofthe supporting member; a transferring unit, which is installed on theelevating and rotating member, for making linear motions to transfersubstrates when the elevating and rotating member moves; a first armwhose one end is supported by the elevating and rotating member to berotatable; a second arm whose one end is supported by the transferringunit to be rotatable and whose the other end is supported by the otherend of the first arm to be rotatable and which is bent; an arm drivingpart, which is installed on the first arm, drives the other end of thesecond arm to pivot on the other end of the first arm to allow the firstarm and the second arm to be folded or unfolded and thus removes thestate of singularity by rotating the other end of the second arm basedon the other end of the first arm to allow the second arm to be unfoldedwith the first arm when a virtual linear line connecting both ends ofthe first arm and that connecting both ends of the second arm arearranged at an overlapped state while the first arm and the second armmove.
 2. The apparatus of claim 1, wherein the second arm is formed in abent shape including a first body part and a second body part; whereinone end of the first body part is supported by the transferring unit tobe rotatable, and one end of the second body part is supported by theother end of the first arm to be rotatable while being rotated by thearm driving part; and wherein the length of the first body part isformed longer than that of the second body part.
 3. The apparatus ofclaim 1, wherein the second arm is formed in a bent shape including afirst body part and a second body part; wherein one end of the firstbody part is supported by the transferring unit to be rotatable, and oneend of the second body part is supported by the other end of the firstarm to be rotatable while being rotated by the arm driving part; andwherein the length of the first body part is formed shorter than, orequally to, that of the second body part.
 4. The apparatus of claim 2,wherein the first body part and the second body part are formed with ashape of either straight line or arc.